1. Field of the Invention
This invention relates to a sea-floor template for the drilling of boreholes, either for anchor piling or wells in the ocean floor. It relates especially to a floating template that has folding arms for ease of transportation and installation.
In recent years there has been considerable attention attracted to the drilling and production of wells located in water. Wells may be drilled in the ocean floor from either fixed platforms in relatively shallow water or from floating structures and vessels in deep water. The most common means of anchoring fixed platforms includes the driving or otherwise anchoring of long piles in the ocean floor. Such piles normally extend above the surface of the water and support a platform attached to the top of the piles. This works fairly well in shallow water, but as the water gets deeper the problems of design and accompanying cost become prohibitive. In deeper water, it will become common practice to drill and produce from a floating structure.
In recent years there has been considerable attention directed toward many different kinds of floating structures. One system receiving attention is the so-called Vertically Moored Platform. Such a platform is described in U.S. Pat. No. 3,648,638, issued Mar. 14, 1972, Kenneth A. Blenkarn, inventor. A chief feature of the disclosure in that patent is that the floating platform is connected to an anchor only by elongated parallel members and the floating structure has buoyancy means designed especially with respect to the trough of a design wave so as to minimize variations in vertical forces imposed on the vertical elongated members which may be caused by passing waves. There are other types of floating drilling structures, such as the semi-submersible and the floating drill ship with a moon-pool or vertical opening through the center through which drilling operations are carried out. The drilling engineer selects a floating vessel which he believes will best fit the environmental conditions which are expected to be encountered.
2. Prior Art
The closest prior art relating to my invention, to the best of my knowledge, concerns templates or frames on the ocean floor having vertical passages through which wells may be drilled. The prior art template is fabricated in a fabrication yard and is a fixed structure. It is transported to a well site at the selected marine location and lowered to the sea floor. None of the prior art of which I am aware has a template with folding arms which is floated to a well site and then lowered with the arms being extended at the well site.